A powered air purifying respirator (PAPR) is a common type of respirator used when working in areas where there is known to be, or there is a risk of there being, dusts, fumes or gases that are potentially hazardous or harmful to health. A PAPR has a turbo unit comprising a fan driven by an electric motor for delivering a forced flow of air to the respirator wearer. One or more filters are fitted to the turbo unit through which air is drawn by the fan. The air is passed from the turbo unit through a breathing tube to a contained wearer environment, such as a face piece, a head piece or a suit, thus providing filtered air to the wearer's breathing zone (the area around their nose and mouth, known as the orinasal area).
A turbo unit for a PAPR may have an electronic control unit to regulate the power driving the fan. Typically, a single power supply, for example a battery pack, provides power for both the fan and the electronic control unit. The electronic control unit may be used to trigger turbo status indicators, for example, to alert the wearer if the airflow falls below a designated level and the designated level of respiratory protection is likely to be compromised. It is also common for the electronic control unit to trigger a status indicator if the battery is depleted to a level where the correct operation of the PAPR is likely to be compromised or to alert the wearer that the filters may be blocked with dust and need to be replaced. Typically turbo status indicators, for example lights and/or buzzers, are mounted on or within the turbo unit housing and arranged to alert the wearer to the current operating status of the turbo unit.
It is usual for the turbo unit to have controls, for example a switch mounted on the turbo unit housing to enable the wearer to turn the turbo unit on and off. Typically, during normal operation of the turbo unit, air should be delivered to the wearer at a predetermined substantially uniform volumetric airflow. The wearer may need to be able to adjust the airflow to a different level, for example if the wearer is working particularly hard and breathing more deeply or at a faster rate than usual, they may desire to increase the airflow. To facilitate this, some turbo units are provided with a control switch on the turbo unit housing to enable the wearer to change the airflow between a discrete range of two, three or more different, pre-set airflow values, for example, 160 liters per minute or 180 liters per minute.
It is common for the turbo unit of PAPRs to be provided with a belt or harness to enable the turbo unit to be secured about the wearer's torso. It is often convenient for the wearer to wear the turbo unit towards the rear of their torso such that it is positioned where it will not interfere with or hinder the work that the wearer is conducting. In these circumstances it may be difficult for the wearer to locate and operate turbo unit controls especially if they out of the range of vision of the wearer. For example, if a turbo unit is provided with an airflow level adjustment as described above, it can be difficult for the wearer to select the correct airflow level if the turbo is out of sight. Furthermore, the wearer may not be able to see visual turbo status indicators that are mounted on the turbo unit. In such situations the wearer relies on hearing an audible indicator and then consults the visual turbo status indicators to diagnose the current operating status of the turbo unit. The above-described situation is often exacerbated by the fact that PAPR wearer containment environments, such as head pieces or masks, can restrict the wearer's peripheral vision thereby limiting the wearer's range of vision.
The use of PAPRs where the wearer containment environment is a full suit has become more popular recently, particularly in emergency response situations. In full suit systems the turbo unit is often enclosed within the suit, such that the wearer does not have access any turbo unit controls. Furthermore, it is often not possible for the wearer to see any turbo unit mounted visual turbo status indicators. Improvements have recently been made to such systems, for example the Chemprotex PRPS (powered respiratory protective suit) system available in the United Kingdom from 3M United Kingdom plc, 3M Centre, Cain Road, Bracknell, RG12 8HT, provides a turbo unit that is modified such that the visual turbo status indicators are located inside the headpiece of the suit in the range of vision of the wearer and connected to the turbo unit via a cable inside the suit.
Such wired solutions as described above provide limited positioning options to suit individual wearer's preference and/or job related preference. The positioning of wired turbo status indicators is often limited to being worn by the PAPR wearer. In many workplace situations, for example working close to rotating machines, the use of wired cables is unlikely to be acceptable due to problem of snagging or entanglement of wires.
It is therefore desirable to be able to use PAPR systems in any type of containment environment whilst giving the wearer easy access to turbo controls and turbo status indicators.